Guam Research Center is concerned with studying etiologic factors, pathogenetic mechanisms and therapeutic approaches to Guamanian amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD). Current projects include: Maintenance of a tissue bank in Bethesda; virologic studies including the search for a possible C-type virus particle; a detailed assessment of immune function including HL-A Typing, enummeration of circulating T-cells by the Rosette Method, the presence of auto-antibodies, lymphocyte transformation to phytohemagglutin and several common antigens such as PPD, Candida, and Streptokinase-Streptodornase as well as mediator production (LI); and study of the long term effects of L-dopa in PD patients.